Peptidergic input to immunohistochemically-identified Renshaw cells.

Peptidergic influences on Renshaw cells were assessed in rat using gephyrin-immunoreactivity, as a Renshaw cell specific marker, in combination with substance P, calcitonin gene-related peptide- and nicotinic acetylcholine receptor-immunolabelling. An average of 3.9 substance P-, and 8.1 calcitonin gene-related peptide-, and 16.3 nicotinic acetylcholine receptor-immunoreactive close contacts or puncta were observed per Renshaw cell. Most appositions were somatic. These results provide neuroanatomical support for the peptidergic modulation of Renshaw cells.